The A-List

Biologist Leads Group That Mapped Crocodilian Genomes

Understanding these reptiles’ genome can help scientists better understand birds.

A Texas Tech University biologist led a team of more than 50 scientists who mapped the genomes of three crocodilians.

By mapping these genomes, scientists may better understand the evolution of birds, which are the toothy predators’ closest living relatives, said David Ray, an associate professor of biology. The team completed genomes of a crocodile, an alligator and a true gharial to complete the genomic family portrait.

Their research, largely funded by the National Science Foundation, will appear Friday (Dec. 12) in the peer-reviewed journal, Science.

“One of the major finds in our case was that crocodilian genomes change very slowly when compared to birds,” Ray said. “We compared both birds and crocodilians to turtles, which are the closest living relatives of the group that includes both birds and crocodilians. We found that they evolved slowly also. The best explanation for this is that the common ancestor of all three was a ‘slow evolver,’ which in turn suggests that rapid evolution is something that evolved independently in birds.”